Spent 7 days on Denver(dream come true!). Rented a POS StumpJumper, great going down but... Started my acclamation at Valmont Bike Park(NE Boulder) Alt. 5180ft. City owned and maintained. Free to the public. Had everything, slope, XC, skills, flow, lil DH, kids trails. Did 14.4 miles here in 1 1/2hrs, 1000ft climbing.
Second ride was at Batasso Preserve, west of Boulder, Alt. 6600ft. First actual mountain ride!!! It's three connector with two loops in between. A vicious climb/descent, mountain side loop, up/down a valley, mountain side loop, up/down a valley. Repeat doing opposite sides of loops as they are directional. Advertised as 6-7 miles, 1000ft climbing. I ended up with 14 miles, 1400 ft climbing as you do the connectors twice and I did a 600ft descent in 1.3 miles 3X! Beautiful trail, in timber flow, tech, cliffs, views, awesome short DH(that someone can drive you back to the top in ten minutes). Any mtb bike could do this trail, just at varied speeds.
Third was Dakota Ridge/Red Rock(west of Denver) Alt. 6600ft. 7-8 miles 1500 ft. Started with a vicious climb up to the ridge, relatively smooth but steep. Toppin the ridge it was super rocky and super beautiful and scenic. You could see all of Red Rock from the top. The descent!!!(North to South)Was the highlight!!! 1.2 miles of rock and dirt(sand) that I have never dealt with. Passed with flying colors. Crossed into Red Rock for a grinding but gradual climb into the big rocks. Topped the rocks, took a moment to look around and began a gradual descent down Village Ride trail ending up across from where I'm parked. This trail is doable with any mtb bike also, as long as your DH game is good for 1.2 miles or skip it/climb it.
My first Colorado rides so just did rides like I do here just with less oxygen.
Favorite overall trail- Batasso Preserve. Had it all.
Favorite Technical DH- south 1.2 miles of Dakota Ridge(Insane!)